Figure 2.

Integration of site-specific H₂O₂ production with redox buffering systems. A, schematic depicting specific flavin- and quinone-mediated sites of electron leak (${\text{O}}_2^{\overline{·}}$ /H₂O₂ production, red type) within the β-oxidation pathway and ETS. B, JH₂O₂ (left y axis) measured in isolated mitochondria from mouse skeletal muscle during basal respiration supported by PCoA (10 μm) plus carnitine (5 mm) followed by the addition of malonate (site II_F inhibitor, 0.5 mm) and AF/BCNU (1 μm/100 μm). The percentage of JH₂O₂ buffered (right of dotted line, right y axis) is as defined in Fig. 1B. C, JH₂O₂ measured as in B followed by the addition of myxothiazol (site III_Q inhibitor, 2 μm), malonate, and AF/BCNU. D, JH₂O₂ measured as in B followed by the addition of myxothiazol and AF/BCNU. All data are means ± S.E. (error bars); n = 5–6 mice/group.